Exercise #10




  • Problem #1 - The original base case 68-h duration simulation was illustrated by an animation showing the sequence of model calculated three hour average concentration in comparison with the measurement data averaged over the duration of the sampling. Reproduce this graphic but use the measurement data corresponding with each sampling period.

  • Hint - Retrieve captex_control.txt and captex_setup.txt from the original CAPTEX configuration and remember that most of the sampling data in captex2_meas.txt are of 6 h duration. If you ignore the 3 h duration samples and then you can start model output at 0300, 0900, 1500, and 2100 hours.

  • Solution - concplot.gif

  • Problem #2 - Continue with the previous problem by creating an animation of the contours using Google Earth. The measurement data can be excluded for this problem.

  • Hint - Rerun the contouring display and select KML/KMZ as the output option.

  • Solution - After opening the HYSPLITconc.kmz file, sequence through the images to optimize the map so that the same domain can be used for all frames. Then starting with the first time period, select the save image button to save each frame to a unique name. Then use the ImageMagick convert command to create the animation. More information about convert can be found by typing it without arguments or in the ImageMagick documentation.

  • Problem #3 - For those comfortable with scripting, recreate the trajectory frequency plot using center-of-mass trajectories rather than original mean-wind calculation. This cannot be done through the GUI.

  • Hint - Edit the trajectory frequency script to include the creation of a namelist option and the additional lines required in the CONTROL file to run the concentration simulation rather than the trajectory simulation.

  • Solution - Using a 1000 particles per center-of-mass trajectory you should find the results very similar to the original simple trajectory calculation. This does not suggest other simulations, with different configurations or time periods, will also give the same results.